The present invention relates to a packaging system comprising an article-to-be-packaged supplying device for supplying articles to be packaged and a packaging bag for covering the articles, to heat sealing mechanisms which arrive at uniform time intervals, in synchronization with the cycle timing of the respective sealing mechanisms.
When, for example, an article to be packaged such as a slab of chicken or a slab of beef, which has had the feathers or skin treated in scalding water, is mechanically packed, in general, the opening of the topmost packaging bag of stacked bags is picked up by a vacuum cup and is caused to open by blowing compressed air into the bag, the bag opening is then stretched over a beak-shaped hopper, and the article is pushed and filled into the bag by passing inside the beak-shaped hopper, as disclosed in JP49-72082A and JP58-203827A. However, the operation of picking up bag openings repeatedly by means of a vacuum cup, against the weight of the bag, necessarily involves the problem of bag opening errors. In other words, although the weight of the bag itself is not a problem, since the bag is stretched like a sail by the air flow and the weight of the bag is added to this, then bag opening errors due to the vacuum cups occur.
In contrast to the prior art examples described above, JP57-37525A (U.S. Pat. No. 4,553,376) discloses a device wherein the end of a continuous tube of film is opened up by a pair of vacuum cups, whilst the film is drawn but, an article to be packaged is conveyed inside the film from the open end thereof, and the film containing the article is then cut to a prescribed length, whereupon the cut film and the article are conveyed together to a seal mechanism. In this device, the tube film opening end and the sealing mechanism are placed opposing each other, and the device inherently involves a two-way motion of the article, namely, a first movement inside the tube film, and then a movement of the article and the tube film together, into the sealing mechanism, and hence there is a problem in terms of efficiency.
The present invention discloses a packaging system comprising an article-to-be-packaged supply device for accommodating an article to be packaged mechanically in a packaging bag, and conveying the article together with a packaging bag, to a rotary vacuum packaging machine, for example, at a good rate of efficiency. The packaging system according to the present invention discloses a sequenced mechanism which eliminates wasted space inside packaging bags, even in the case of bag opening errors or indefinite articles to be packaged, and moreover a mechanism for unmanned operation. The composition of the present invention is a packaging machine wherein a portion of a winding path of a taped bag formed by attaching the openings of respective bags stacked in a scale-like fashion onto an adhesive tape, is formed horizontally, the opening of the foremost packaging bag hanging down from the adhesive tape in the horizontal portion of the travel path is pulled downwards and opened by vacuum cups, a beak-shaped hopper which opens in the upward and downward direction is inserted inside the opening of the packaging bag, the packaging bag is peeled off from the adhesive tape, and furthermore, an article to be packaged is accommodated inside the packaging bag via the hopper by means of an insertion rod which follows the course of the hopper, the opening of the packaging bag being sealed when the packaging bag has been placed in a vacuum state by means of a rotary vacuum packaging machine; wherein it comprises: means for limiting the amount of movement of the respective front ends of the hopper and the insertion rod to a position up to the inner side of a circulating sealing platform; means for restricting the sliding motion of the packaging bag by pressing the bag opening against the hopper by means of a frictional element which presses on the under side of the hopper; means for blowing compressed air injected onto the upper face of the hopper, inside the packaging bag along the upper face of the hopper, and also blowing same inside the packaging bag via the interior of the hopper as the hopper advances; and means for advancing a pair of opening and closing bars provided below the hopper, together with the hopper to the limit region, and temporarily standing by in the region after the hopper has been withdrawn, and causing the opening of the packaging bag to be stretched along the sealing platform by opening in the opposite directions with the aforementioned standby period.
The opening of the foremost packaging bag hanging down from the adhesive tape tends to open automatically due to the effects of gravity, and since a structure is adopted wherein the openings of the packaging bags are pulled downwards by vacuum cups, opening errors are reduced in advance, even if there is an air flow acting on the packaging bags. Moreover, by adopting means for blowing compressed air injected onto the upper face of the hopper inside the packaging bag, using the angle of incidence of the upper face of the hopper, and also blowing the air into the packaging bag via the interior of the hopper, as the hopper advances, the packaging bags are opened in an efficient manner and the insertion of the hopper is performed reliably.
By adopting means for restricting the movement of the respective ends of the hopper and insertion rod, to the inner side of the circulating sealing platform, the rear end of the article inserted with the packaging bag is restricted to the inner side of the sealing platform, and consequently, no wasted space is formed inside the packaging bag, and moreover, by adopting means for restricting the sliding motion of the packaging bag by pressing the bag opening against the hopper by means of a frictional element which presses on the under side of the hopper, scattering of the article due to the pushing momentum is reduced, and no wasted space is formed inside the packaging bag.